Search with the cn=monitor base

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You can search the cn=monitor base to determine the directory server status, such as cache configuration status, operation counts, connection type counts, and status of service.

To retrieve the directory server status, run the ldapsearch command with the cn=monitor base. For example:

ldapsearch -h ldap_host -p port -s base -b cn=monitor objectclass=*

where, ldap_host is the host name or IP address of the LDAP host.

The cn=monitor search returns some of the following attributes of the directory server:

CN=MONITOR
The search base for the command.
version=IBM Security Verify Directory (SSL), 10.0.1
The version of IBM® Security Verify Directory.
totalconnections
The total number of connections since the server was started.
currentconnections
The number of active connections.
maxconnections
The maximum number of active connections allowed.
writewaiters
The number of threads that send data back to the client.
readwaiters
The number of threads that read data from the client.
livethreads
The number of worker threads that are used by the server.
filter_cache_size
The maximum number of filters that are supported by the cache.
filter_cache_current
The number of filters currently in the cache.
filter_cache_hit
The number of filters that are retrieved from the cache rather than being resolved in DB2®.
filter_cache_miss
The number of filters that were not found in the cache that then needed to be resolved by DB2.
filter_cache_bypass_limit
Search filters that return more entries than this limit are not cached.
entry_cache_size
The maximum number of entries that are supported by the cache.
entry_cache_current
The number of entries currently in the cache.
entry_cache_hit
The number of entries that were retrieved from the cache.
entry_cache_miss
The number of entries that were not found in the cache that then needed to be retrieved from DB2.
acl_cache
A boolean value that indicates whether the ACL cache is active (TRUE) or inactive (FALSE).
acl_cache_size
The maximum number of entries in the ACL cache.
currenttime
The current time of the server. The current time is in the following format: 
year month day hour:minutes:seconds GMT
If expressed in local time the format is: 
day month date hour:minutes:seconds timezone year
starttime
The time the server was started. The start time is in the following format: 
year month day hour:minutes:seconds GMT
If expressed in local time the format is 
day month date hour:minutes:seconds timezone year
en_currentregs
The current number of client registrations for event notification.
en_notificationssent
The total number of event notifications sent to clients since the server was started.

The following attributes are for operation counts:

bindsrequested
The number of bind operations that are requested since the server was started.
bindscompleted
The number of bind operations that are completed since the server was started.
unbindsrequested
The number of unbind operations that are requested since the server was started.
unbindscompleted
The number of unbind operations that are completed since the server was started.
addsrequested
The number of add operations that are requested since the server was started.
addscompleted
The number of add operations that are completed since the server was started.
deletesrequested
The number of delete operations that are requested since the server was started.
deletescompleted
The number of delete operations that are completed since the server was started.
modrdnsrequested
The number of modify RDN® operations that are requested since the server was started.
modrdnscompleted
The number of modify RDN operations that are completed since the server was started.
modifiesrequested
The number of modify operations that are requested since the server was started.
modifiescompleted
The number of modify operations that are completed since the server was started.
comparesrequested
The number of compare operations that are requested since the server was started.
comparescompleted
The number of compare operations that are completed since the server was started.
abandonsrequested
The number of abandon operations that are requested since the server was started.
abandonscompleted
The number of abandon operations that are completed since the server was started.
extopsrequested
The number of extended operations that are requested since the server was started.
extopscompleted
The number of extended operations that are completed since the server was started.
unknownopsrequested
The number of unknown operations that are requested since the server was started.
unknownopscompleted
The number of unknown operations that are completed since the server was started. Unrecognized operations are rejected with a message is sent to the client, which might include the LDAP_UNWILLING_TO_PERFORM result code.
opsinitiated
The number of initiated requests since the server was started.
opscompleted
The number of completed requests since the server was started.
entriessent
The number of entries that are sent by the server since the server was started.
searchesrequested
The number of initiated searches since the server was started.
searchescompleted
The number of completed searches since the server was started.

The following attributes are associated with the server log counts:

slapderrorlog_messages
The number of server messages that are recorded since the server started or since a reset.
slapdclierrors_messages
The number of DB2 error messages that are recorded since the server was started or since a reset.
auditlog_messages
The number of audit messages that are recorded since the server was started or since a reset.
auditlog_failedop_messages
The number of failed operation messages that are recorded since the server was started or since a reset.

The following attributes are for connection type counts:

total_ssl_connections
The total number of SSL connections since the server was started.
total_tls_connections
The total number of TLS connections since the server was started.

The following attributes are for tracing:

trace_enabled
The current trace value for the server. If the server is set to collect trace data, the value is TRUE, or else the value is FALSE.
trace_message_level
The current ldap_debug value for the server. The value is in hexadecimal form, for example: 
0x0=0
0xffff=65535
trace_message_log
The current LDAP_DEBUG_FILE environment variable setting for the server.

The following attributes are for denial of service prevention:

available_workers
The number of worker threads available for work.
current_workqueue_size
The current depth of the work queue.
largest_workqueue_size
The largest size that the work queue reached.
idle_connections_closed
The number of idle connections closed by the Automatic Connection Cleaner.
auto_connection_cleaner_run
The number of times that the Automatic Connection Cleaner process run.

The following attribute is for alias dereference processing:

bypass_deref_aliases
The server runtime value that indicates whether alias processing can be bypassed. The value is TRUE if no alias object exists in the directory, and FALSE if at least one alias object exists in the directory.

The following attributes are for the attribute cache:

cached_attribute_total_size
The amount of memory that is used by the directory attribute cache, in KB. This number includes the additional more memory that is used to manage the cache and is not charged to the individual attribute caches. If the total is larger than the sum of the memory that is used by all the individual attribute caches.
cached_attribute_configured_size
The maximum amount of memory, in KB, for use by the directory attribute cache.
cached_attribute_hit
The number of times the attribute is used in a filter and is processed by the attribute cache. The following value is generated in output: 
cached_attribute_hit=attrname:#####
cached_attribute_size
The amount of memory that is used for this attribute in the attribute cache. The following value in KB is generated in output: 
cached_attribute_size=attrname:######
cached_attribute_candidate_hit
A list of up to 10 most frequently used non-cached attributes that are used in a filter that can be processed by the directory attribute cache. The following value is generated in output: 
cached_attribute_candidate_hit=attrname:#####

You can use this list to help you decide which attributes you want to cache. Typically, you want to put a limited number of attributes into the attribute cache because of memory constraints.

Examples

You can use the following examples to calculate throughput and workload on the server from the output that is returned by the ldapsearch command.

Throughput example
You can calculate the throughput of the server by monitoring the directory server statistic called opscompleted. This statistics value indicates the number of operations that are completed since the LDAP server started.
To determine the throughput, find the values for the opscompleted attributes by issuing two ldapsearch commands. To monitor the performance statistics, run the first ldapsearch at time t1 and the other at time t2. For example, opscompleted (t1) and opscompleted (t2).
The average throughput at the server during the interval between t1 and t2 can be calculated as:
(opscompleted(t2) - opscompleted(t1) - 3)/(t2 -t1)
A value of 3 is subtracted to account for the number of operations that are of the ldapsearch command.
Workload example
You can determine the server workload from the output values from the ldapsearch command with the cn=monitor base. For example, you can calculate the number of add operations that were completed in a certain amount of time.
To determine the number of add operations against the server in a time interval, find the values for the addscompleted attributes by issuing two ldapsearch commands. To monitor the performance statistics, run the first ldapsearch at time t1 and the other at time t2. For example, addscompleted (t1) and addscompleted (t2).
The number of add operations that are completed by the server during the interval between t1 and t2 can be calculated as: 
(addscompleted(t2) - addscompleted(t1)/(t2 -t1)
You can find the workload on the server for the other operations, such as searchescompleted, bindscompleted, deletescompleted, and modifiescompleted.